Machine for testing the bending strength of metal strips



FeB.-4, 1930.

J. H. NEAD ET AL MACHINE FOR TESTING THE BENDING STRENGTH OF METALSTRIPS Filed Aug. 25, 1927 2 Sheets-Sheet A TTORNE Y.

Feb. 4, 1930. J. H. NEAD ET AL MACHINE FOR TESTING THE BENDING STRENGTHOF METAL STRIPS Filed Aug. 25, 1927 2 Sheets-Sheet My 34 INVENTOR ATTORNE Y.

Patented Feb. 4, 1930 UNITED STATES PATENT OFFICE JOHN H. NEAD, REIDL'KENYON, AND CLARENCE W. RUST, OF MIDDLETOWN, OHIO, ASSIGNORS TO THEAMERICAN ROLLING MILL COMPANY, OF MIDDLETOWN, OHIO,

A CORPORATION OF OHIO MACHINE FOR TESTING THE BENDING STRENGTH OF METALSTRIPS Application filed August 25, 1927. Serial No. 215,466.'

- Our invention relates to machines for testing the bending strength ofmetal strips, and particularly to a motor driven machine for thispurpose,

Broadly, it is our object to mount a scale beam so that the bendingstrength of a piece of metal or other material to be bent, may beregistered in terms of units of load required. A simple type of machinefor this purpose may be made by mounting a scale so that the beam of thescale will be attached to a bending bar. The piece to be bent and testedmay be held in a fixedly mounted member above the bending bar, and thescale moved away from the mounting member, or vice versa, with theresult that the force which is required by the bending bar to bend thesample is registered on the scale.

It is a specific object of our invention to provide improvements whichwill tend to avoid inaccuracies in such types of machines. In ourpreferred form it is our object further to provide a machine which maybe operated by a constant source of power such as will be provided by anelectric motor. The above and other objects to which reference will bemade during the ensuing disclosure we accomplish by that certainarrangement and combination of parts of which we have shown a preferredembodiment.

In the drawings Figure 1 is a side elevation of our improved testingmachine.

Figure 2 is a perspective view of the machine shown in Figure 1.

Figure 3 is an end elevation of the machine.

Generally indicated at 1 we. have shown the frame of the machine. Withina channeled portion 2 there is mounted a carriage 3 having samplesupporting portions 4, and with overhanging ledges 5 which retain theends of the strip of metal to be tested. The carriage is pivotallysupported by a link 6, and a counter-weight 7, secured to a cable 7passes around the pulleys 8 and is attached to the end of the link 6 soas to counterbalance the weight of the carriage. The link 6 has rackteeth 9 which are engaged by a pinion 10 which is rotated through achain of gears 11, 11, operatively connected with an electric mo- Ipinion 10.

tor 12. It will be' observed that the link 6 may be inclined to the leftto disengage the pinion. A pivoted handle 13 journaled in the machineframe at 14 has a roller 15 which, when it is desired to move the rackinto engagement with the driving pinion, is depressed, thereby tiltingthe link to the right. \Vhen it is desired to release the engagement ofthe rack with the pinion, the operator releases the handle and thecounterweight may be caused to rock the link to the left, in whichposition it is disengaged. In order to make the releasing action morepositive, we also preferably attach a spring 16 to the frame 1, and weattach the other end of the spring to the link. This arrangement, whichis illustrated in Figure 1, normally pulls the link to the left so thatit requires some slight downward pressure on the handle 13 to bringabout the engagement of the rack 9 and the The tool or bending bar whichwe prefer to use to bend the metal strip which we have indicated indotted lines at 16, has a strip engaging upper face 17 and a body 18which is slidably mounted in a substantially vertical walled aperture 19in the supporting plate 4. The lower end of the body 18 has a bearing 20which is carried by an arm 21 of a pivoted lever. Intermediate the endsof the lever we have shown a bearing 23. The lever having 7 the portions21, 22, has a fulcrum bearing 24 which is adjustable by means of anadjusting screw 25. The bearing 23 is mounted in a cross member 26extending between suspended links 27. The links are carried by a bearing28 located intermediate the fulcrum bearing 29 of another lever and thearm thereof.

This upper lever has at the end opposite the fulcrum a bearing 30 whichis so disposed as to bear against a hooked frame 31 which engages thebalance arm or beam 32 of a scale generally indicated at 33.

For enabling accurate setting of the several parts of the balancingmechanism eonnccted with the scale, we have shown the adjustable support36 which controls the height of the scale, and the adjustable carriage34 which controls the position of the fulcrum bearing 29.

The adjusting screws 25 and 35 are used to secure the proper alignmentof the lower beam 21, 23. When the knife edge 24 is bearing on the lowerend of 25 as a fulcrum point the lever ratio of the beam system is suchthat the load applied at the point of contact with the sample at 17 isequal to the load transmitted to the scale beam at 32. By raising thefulcrum 35 until in contact with the knife edge 37 and backing off thefulcrum 25 until free from the knife edge 24, the flever ratio may bechanged so that the load transmitted to the scale beam at 32 is somefraction of the load applied at the point of contact with the sample at17. In the particular case illustrated this is one tenth although thisvalue may be made different in order to per.- mit operation of themachine over other ranges of loads.

When the lever ratio is changed from one to-one to one-to-ten or to someother ratio as indicated above it will be necessary to change the zeroadjustment of the scale on account of the change in the dead load of theleyer system on the scale beam 32 brought about by a change in fulcrumpoints.

The operation of testing a piece of metal will now be described. Thepiece of metal cut to size and of a known gauge is inserted on thesupporting parts 4 as indicated at 16. The motor is then turned on andthe pinion 10 begins to rotate. The handle 13 is then depressed and therack beginsto force down -the carriage 3. The piece of metal being heldbetween the overhanging ledges 5 will be moved down into engagement withthe face 17 of the member 18. The member 18 will at first beardownwardly against the arm 21 of the lower lever and through the connection with the upper lever the scale will begin to progressively indicatethe increased downward pressure in the terms to which the indicia aregraduated.- As the carriage 3 is forced downward the sample bends moreand more and as it does so the load increases until a certain point,which is characteristic of the material, at which there is little or noincrease in the load, although the bending continues at a uniform rate,This is a definite point and is characteristic for a given material andis taken as the end point of the test.

The motor is preferably geared so that the movement of the carriagedownwardly will be gradual, so that it will be simple for the persontesting the metal strip to establish his end point which is, as will bereadily understood, that point at which there is nofurther progressiveincrease in the scale 'reading.

Having thus described our invention, what we claim as new and desire tosecure by Leted. a member adapted to bear against a sample intermediatethe ends thereof while said sample is disposed on said carrier, saidmember guided by said carrier. and movable relatively thereto, a scalehaving a balance beam operatively connected with said member, and meansfor moving said carrier, whereby said member is thrust against saidsample to be tested, and the force required to bend said sampleregistered on said scale.

2. A machine for testing bending strength, comprising a carrier for asample to be tested, a member adapted to bear against a sampleintermediate the ends thereof while said sample is disposed on saidcarrier, said member guided by said carrier and movable relativelythereto, a scale having a balance beam operatively connected wlth saidmember, and means for moving said carrier, whereby said member is thrustagainst said sample to be tested, and the force required to bend saidsample registered on said scale, and means for retaining said sample onsaid carrier.

3. A machine for testing bending strength, comprising a carrier for asample to be tested, said carrier having an opening therein, a memberadapted to bear against a sample intermediate the ends thereof whilesaid sample is disposed on said carrier, said member havingrelativemovement with relation to said carrier, a scale havin a balance beamoperatively connected with said member, and means for moving saidcarrier, whereby said member is thrust against said sample to be tested,and the force required to bend said sample registered on said scale andmeans for retaining said sample on said carrier, and said memberslidable throughsaid opening in said carrier.

4. A machine for testing bending strength, comprising av carrier for asample to be tested, a member adapted to bear against a sampleintermediate the ends thereof while said sample is disposed on saidcarrier, said member having relative movement with relation to saidcarrier, a scale having a balance beam operatively connected with saidmember, and means for moving said carrier, whereby said member is thrustagainst said sample to be tested, and the force required to bend saidsample registered on said scale, said means for moving said carriercomprising a motor and a chain of gears with a rack operativelyconnected with said carrier which one of said chain of gears is adaptedto engage, and manually operative means for inhibiting the engagement ofsaid gear and rack.

intermediate the ends of said strip in a direc tion away from saidcarrier portion against a metallic strip disposed on said carrierporbend said metallic strip.

6. A bend testing machine having a carrier on which a metallic strip tobe tested may be disposed, a bending bar having relative movement withrelation to said carrier adapted to bear against a metallic stripdisposed on said carrier intermediate the ends of said strip, means forinducing relative movement between said carrier and-said bending bar,and means for indicating the pressurerequirjed by said bending bar tobend said metallic strip, said means-for inducing relative movementcomprising means actuative by a constant force with means for inhibitingthe application of said force to said means.

7. A bend testing machine having a carrier on which a metallic strip tobe tested may be disposed, a bending bar having relative v n. movementwith relation to said carrier adapted to bear against a metallic stripdisposed on said carrier intermediate the ends of said strip, means forinducing relative movement between said carrier and said bending bar,and means for indicating the pressure required by said bending bar tobend said metallic strip, said means for indicating pres-.

sure comprising a scale with a series of levers operatively connectedwith said bending bar, and means for shifting the fulcrum of at leastone of said levers.

8. A bend testing machine having a carrier on which a metallic strip tobe tested may be disposed, a bending bar having relative movement withrelation to said carrier adapted to bear against a metallic stripdisposed on said carrier intermediate the ends of said strip, means forinducing relative movement between said carrier and said bending bar,and means for indicating the pressure required by said bending bar tobend said metallic strip, and means for counterbalancing the weight ofsaid carrier.

9. A bend testing machine having a. counterbalanced carrier on which ametallic strip to be tested may be disposed, a bending bar havingrelative movement with relation to said carrier adapted to bear againsta metallic strip disposed on said carrier intermediate the ends of saidstrip, a scale having a balance beam connected through a series ofbalance levers, one lever being fulcrumed to said bending bar, andmechanical means for inducing relative movement of said carrier andbending ba'r, whereby the force required to bend said strip may beindicated.

10. A bend testing machine havin a coun terbalanced carrier on which ameta lic strip to be tested may be disposed, a bending bar havingrelative movement with relation to said carrier adapted to bear againsta metallic strip disposed on said carrier intermediate the ends of saidstrip, a scale having a balance beam connected through a series ofbalance levers, one lever being fulcrumed to said bending bar, andmechanical means for inducing relative movement of said carrier andbending bar, whereby the force required to bend said strip may beindicated, said means to induce relative movement of said bending .barand carrier comprising an electric motor with inhibitive mechanicalmeans connecting said motor'and carrier.

11. A bend testing machine having a counterbalanced carrier-on which ametallic strip to be tested may be disposed, a bending bar havingrelative, movement with relation to said carrier adapted to bear againsta metallic strip disposed on said carrier intermediate the ends of saidstrip, a scale having a balance. beam connected through a series ofbalance levers, one lever being fulcrumed to said bendingbar, andmechanical means for inducing relative movement of said carrier andbending bar, whereby the force required to bend said strip may beindicated, said levers being so arranged with relation, one to another,that one lever is suspended. from the other, the suspending lever beingconnected with the beam of ascale, and the suspended lever beingconnected with said bending bar.

12. A bend testing machine having a counterbalanced carrier on which ametallic strip to be tested may be disposed, a bending bar havingrelative movement with relation to said carrier adapted to bear againsta metallic strip disposed on said carrier intermediate the ends of saidstrip, a scale having a balance beam connected through a series ofbalance levers, one lever being fulcrum'ed to said bending bar, andmechanical means for inducing relative movement ofsaid carrier andbending bar, whereby the force required to bend said strip may beindicated, said levers being so arranged with relation, one to another,that one lever is suspended from the other, the suspending lever beingconnected with the beam of a scale, and the suspended lever beingconnected with said bending bar, and means for adjusting the positionsof the fulcrums of said levers.

13. A bend testing machine having a supporting frame, a carrier slidablymounted with relation to said frame, means for counterbalancing theweight of said carrier, said carrier having means for retaining thereona metallic strip to be tested, a bendlng bar extending loosely throughsaid carrier, said bar operatively connected with an indicating scale,and motor actuative means for moving said carrier so that a stripretained thereon will be carried into engagement with said bending bar,and the load required to bend the piece registered on said indicatingscale.

14. A machine for testing the bending strength of a piece of metalcemprising a member for engaging said metal piece inter mediate itsends, and a member having means to engage the ends of the materialoutside of said first mentioned member, and a means for moving one ofsaid members by a steady force toward the other, and a pressureindieating device connected to said other member so as to continuouslyindicate the pressure imparted to said other member, this connectionbeing made through a system of beams and levers with adjustable fulcrumpoints arranged so as to permit employment of different lever ratios fortransmitting the pressure from said other member to the pressureindicating device, whereby when the pressure indications cease to rise,an indication Wild be given which provides the factor for which the testis made.

JQHN H. NEAD.

REID L. KENYON.

CLARENCE V7. RUST.

